EverCool launched its newest line of performance case fans with the Silent Shark Fan series, the first member of which, is the SSF-12. The 120 mm SSF-12 uses seven blades with sawtooth-shaped vanes at the ends, which work to increase air-flow, and the shape of which is inspired by shark gills. The impeller is suspended on what EverCool refers to as "ever lubricated" (EL) bearing.

The SSF-12 is designed to spin at speeds ranging between 800 and 1400 RPM ±15%, with noise output ranging between 19 and 26 dBA. It uses a conventional 120 x 120 x 25 mm opaque black frame. The fan uses a conventional 3-pin connector to draw power, and includes a rotary speed control module that spins it between its advertised speed range. It also includes white rubber bolts as alternatives to metal screws, which absorb vibrations and minimize noise.

i mean at 90degress to the rotor in the middle. they are perpendicular to the curved surface of the rotor unlike the CM 90CFM ones (for ref)
and when i said they will make very little airflow is because they will have to be run pretty slow to be silent. as the steep angle produces a lot of drag and wooshy noise.